Manufacture of bituminous emulsions



Patented pr. l, 1930 JOHN STROTHER MILLER, JR, RAHWAY, NEW JERSEY, ASSIGNOR TO THE BARBER ASPHALT COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF WEST VIRGINIA MANUFACTURE OF BITUMINOUS EMULSIONS 7 No Drawing.

My invention relates to bituminous emulsions for suspensions and their manufacture,

and is especially concerned with the emulsification of relatively hard bitumens and bituminuous materials solid at ordinary temperatures. For convenience, I have hereinafter referred to bitumens and bituminous materials generally as bituminous bases, 01, still more briefly, as bases.

The common commercial processes of aqueously emulsifying bituminous bases involve direct and intimate intermixture of the base in a suficiently fluid state with water. In many or most cases, this requires thatboth the base and the water be heated; the base to render it sufliciently fluid, and the water in order that the attempted intermixture may not chill the base so much as to render emulsive combination impossible. To avoid chilling troubles, therefore, the Water must be raised as nearly as possible to the tempera ture of the base when fluid; so that the ap-" plication of this process of emulsifying by direct fluid intermixture is limited to bases of not more than moderate hardness at ordinary temperatures. Solid bituminous bases of consistency harder than mm. when tested with a standard Roberts-Sharp #2- needle under a load of 100 grammes acting for 5 seconds at 77 F. (according to the standard method of the American Society for Testing Materials) have generally proved impracticable of emulsification by such a process. Ac-

1 and unsatisfactory,-owing, in part, to the operations necessary for the recovery pf the solvent used Y'Moreoverfits apphcatlon 1s Application filed July 17, 1920. Serial No. 397,027.

necessarily limited to the bases for which suitable solvents are commercially available,

My invention makes it possible to emulsify solid bituminous bases,whether natural or artificial, and Whether simple, fluxed, or otherwise composite,-without the aid' of solvents, and without necessity of softening them by heat. Such emulsification can be effected without dependence upon heat, I have discovered, by bringing the solid base into in; termixture with the desired liquid medium while or'after reducing it to a suitably fine state of division-all at ordinary temperatures or in the cold. The bituminous dispersion or suspension produced by this process of direct solid and fluid intermixture in the. cold has all the useful properties of so-called bituminous emulsions of the prior art produced by direct fluid intermixture with the aid of heat, and may, therefore, fairly be regarded as an emulsion. And even though the bituminous particles of this dispersion or suspension be not in the globular fluid state characteristic of emulsions strictu sensu, yet since many of the bases heretofore emulsi ed by direct fluid intermixture with the aid of heat are solid when cold, it would appear that in all probability the suspended bituminous globules of their emulsions so produced are solid rather than liquid after 0001- ing of the emulsion, and that my products are emulsions in the same sense that they are.

Aqueous emulsions of solid natural orartificial bituminous bases, and more particularlyemulsions of solid asphaltum bases, as native asphalt, gilsonite, petroleum still residues, and the like, may be prepared on this principle with mechanical reduction of the, base in its solid state to a finely divided condition, by grinding, mixing, and emulsivel 9e combining the base (either crude or refined with water in the presence of an emulsifying or peptonizing material or agent, prone to or promotive of emulsification,such as soap, starch, finely divided mineral or inorganic material like clay, etc. Natural asphalts ordinarily requiring to be refined (such as Trinidad Lake, Bermudez Lake Maracaibo, etc.) may be thus finely ground unrefined, or in their crude-native state, in

. ties the presence of water and emulsifying agent. In thus emulsifying such natural asphalts unrefined, due allowance for their natural water content should be made in adding water to give the amount desired in the final product; while in emulsifying refined natural as phalts, artificial asphalts, tar, and other water-free bituminous bases, the full amount of water desired must be added.

Bituminous emulsions prepared by such direct intermixture with mechanical division difier from those prepared with the aid of heat in the roughness, irre ularity, and angularity of their suspended nely divided or ground particles as contrasted with the smooth roundness of solidified lobules of liquid base. Such roughness an irregularity tend to greater resistance of the particles against settling out or breaking of the emulsion, so that the emulsion thus produced is essentially a new manufacture, and thoroughly stable. The particles are in a' colloidal or semi-colloidal state of finenessv and thoroughly deflocculated, so that they do not tend to adhere together until on unless the emulsion is dried or otherwise broken. The emulsion is creamy in appearance and feel, not at all sandy.

In contrast to artificial bitumens like coaltar pitch or water-gas pitch, certain hard natural bitumens orbases in their native state show emulsification or emulsifying proper- (or both) in greater or less degree, either by reason of emulsive combination in them 0 a water content that gives them somewhat the character of solid emulsions, or by reason of the presence in them, as impurity, of material having emulsifying prop- K erties. Such natural bitumens, I have discovered, may be emulsified by being finely ground in the presence of water without the addition of any foreign emulsifying agent, or with a less addition than would otherwise byrequired. An example of such a natural self emulsifying base is crude Trinidad Lakeasphalt, which contains emulsient finely divided inorganic material of clayey character that acts as an emulsifyin agent when the base is ground as hereinbefore mentioned, as well as some emulsively combined native water. 4

My invention, it will be seen, not only serves for the emulsification 'ofreven the hardest bituminous bases by and of themselves, but also affords a means of producing a useful emulsion compositions or combinations of ingredients that could not readily be incorporated together in the way of fluxing, or of hard and soft bituminous components generally. When such emulsion combinations of hard and soft bases are desired, the hard base may. be ground and mixed, in the presence of an emulsifying agent, with water and emulsively sus ended soft base. The

grinding of the bar base in the presence of cal emulsion of Trinidad Lake asphalt, t e

proportions mentioned being by -w eightr P ts Crude Trinidad Lake asphalt 57 Water ...L.. 29 Rosin oil soda soap: l 5

The hard base should first be broken or crushed (coarsely ground) into conveniently small fragments and grains; it should then be ground with the water and the soap in a ball-mill until the bituminous mass becomes thoroughly homogeneous, when the finely ground base will be found to have become thoroughly intermixed and emulsively com bined with the water a d the emulsifying agent. The resultant prd d lct has the useful properties characteristic of bituminous emulsions generally, with the special advantages due to the hardness of its bituminous content.

The total amount of soa or other emulsifying material (whether Foreign like soap, or of a character native to the bitumen, like the. clay of Trinidad Lake asphalt) that shouldbe present is subject, of course, to considerable variation, according to the stability of the product desired under all conditions of thinning with water. The thinner the emulsion it is desired to produce (either initially or by subsequent thinning for use),-

the higher the proportion of soap to bituminous base should be. The proportions indicated are about right for good economy, and will insure a product sufiiciently liquid to flow readily. j

The bituminous emulsion produced as just described is suitable and desirable for various special purposes,such as. flooring. mixtures, mastic mixture for vertical walls, and/for some forms of water-proofing, etc. For many purposes, indeed, its bituminous content is too hard; but this can readily be softened by no I admixture or intermixture of soft bituminous emulsion (made with 'a relatively soft base by any known or preferred process) with the hard emulsion, according to the methods indicated above. Soft base emulsions can be very readily made fromv liquid petroleum fluxes by methods well known to the art; and by proper mixing of such emulsified flux or the like with my hard base emul- ,sion, the consistency of the total base or resie due of the emulsion combination can be varied.

at will from that of the hard base to'that. of

pose for which bituminous materials are' useful.

- Having thus described my invention, I claim:

1. The process of preparing an aqueous emulsion of natural solid bituminous base self-emulsifying by reason of native impurity which consists in finely grinding such base, in its solid native state, with water and continuing the grinding until a water external phase emulsive combination is efiected.

2. The process of preparing an aqueous emulsion of natural solid bituminous base natively containing emulsifying finely divided material which consists in mechanically reducing the base in its solid native state to a condition of fine division in the presence of water and intimately mixing the solid base thus finely divided with the water until a water external phase emulsive combination is effected.

3. The process of preparing aqueous emulsion combinations of hard and soft asphaltum bases which consists in finely grinding the hard base and mixing the same, in the presence of an emulsifying agent and in the solid state, with water and with emulsively suspended soft base.

4. As a new manufacture, fluid aqueous bituminous emulsion comprising hard natural asphaltum base in the solid state, finely ground and emulsively combined with water and a native content of emulsifying finely divided material with water in the external phase.

5. As a manufacture, an aqueous bituminous emulsion comprising finely ground hard asphaltum base in the solid state, mixed and emulsively combined with water and with emulsively suspended soft bituminous base with water in the external phase.

6. The process of preparing a thoroughly stable fluid emulsion from a solid asphaltum base by direct intermixture in the cold of such base with a desired liquid medium, which includes grinding a solid asphaltum base to a degree of fineness at which it will emulsively combine with a desired liquid medium in a solid state and without dependence upon heat and efiecting an emulsive combination of the finely ground base witha desired liquid medium in external phase in the presence of an emulsifying material.

7. The process of preparing a thoroughly stable fluid emulsion from a solid asphaltum base by direct inter-mixture in the cold of such base with water, which includes grinding a solid asphaltum base in the presence of water to a degree of fineness at which it will emulsively combine with the water in a solid state without dependence upon heat and continuing the grinding in the presence of an emulsifying material to effect an emulsive combination of the base and the water with the water in external phase.

v8. The process of preparing a thoroughly stable fluid emulsion from a solid asphaltum base by direct intermixture in the cold of such base with water, which includes grindinga solid asphaltum base in the presence of water to a degree of fineness at which it will emulsively combine with the water in a solid state Without dependence upon heat and continuing the grinding in the presence of finely divided inorganic emulsifying material to effect an emulsive combination of the base and the water with the water in external phase.

9. As a new article of manufacture a fluid aqueous bituminous emulsion comprising a finely ground asphaltum base the particles of which are emulsively combined in the solid state with water and emulsifying material, the water being in external phase.

10. The process of preparing an emulsive combination of a non-fluid asphaltum, which includes grinding a non-fluid asphaltum with a liquid medium containing a protective colloid until the asphaltum reaches a degree of fineness such as to emulsively combine with the liquid medium.

In testimony, whereof, I have hereunto signed my name at Maurer, N. J this 15th day of July, 1920. r I

JOHN STROTHER MILLER, JR. 

